It is necessary to provide an image processing function to a copy machine etc., because in such image processing system usually needs functions of enlargement, diminishment and so forth, so a lot of optical systems are indispensable. The optical system had a contradictory subject to decrease aberration and to compact the size: it is difficult to compact a system in order to guarantee the quality of the processed image. Concerning to the optical technology, compactness and costdown is prevented by mechanical technological components such as adjustment of optical axis, cleaning of a surface for receiving light, controlling vibration, protecting friction in the movable part and so on.